Automatic grinding machine



y 1938- 1 H. A. SILVEN 2,117,917

- AUTOMATIC GRINDING MACHINE Filed Oct. 4, 1957 6 sheets-Sheet 1 FIE-7.11

y 7, 1938. Y H.111. SILVEN 2,117,917

AUTOMATIC GRINDING MACHINE Filed Oct. 4, 1937 6 Sheets-Sheet 2 FIG. 2

Dame/M101 HERBERT A. SILVEN 5 374 70 72 WU.W W

May 17, 1938. H. A. SILVEN 2,117,917

AUTOMATiC GRINDING MACHINE Filed Oct. 4, 1957 6 Sheets-Sheet 3 May 17,1938. 1-1. A. SILVEN AUTOMATIC GRINDING MACHINE Filed Oct. 4, 1937 6 Sheets-Sheet 5 N E t W v v NR m L 3 I 5 DR. 1 1 A 1 Lvwm 9m hvw M U xvw E hmw O o o s .26 o 9v 0 R 1 Em E llllll l l LIK 1 H W N 1. I... QM W 3m 5N vm w 3w 9% m wmm a. mum Q m.

Patented May 17, 1938 2 117 917 v UNITED STATES PATENT OFFICE AUTOMATIC GRINDING MACHINE Herbert A. Silven, Worcester, Mass., assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application October 4, 1937, Serial No. 167,131 1'! Claims. (Cl. 51--105) This invention relates to grinding machines, Fig. 1 is a front elevation of a grinding maand more particularly to a full automatic grindchine embodying this invention; ing machine for grinding cylindrical work pieces. Fig. 2 is a piping and electrical diagram show- One object of the invention is to provide a siming the electrical and fluid pressure connections 5. ple, thoroughly practical, improved full automatic between the various units and control valves; grinding machine. Another object of the inven- Fig. 3 is a left hand end view of the left-hand tion is to provide a hydraulically actuated full work head, taken approximately on the line 3--3 automatic grinding machine in which the various of Fig. 1, on an enlarged scale, with the motor remechanisms are provided with safety interlocks. moved;

A further object of the invention is to provide a Fig. 4'is a horizontal sectional view through 10 full automatic hydraulically operated cylindrical both of the work heads, taken approximately on grinding machine in which the various hydraulic the line 4-4 of Fig. 3; control units are electrically interlocked. An- Fig. 5 is a cross sectional view, on an enlarged other object of the invention is to provide an scale, through the work feeding and discharging automatic work loading mechanism or carrier mechanism, taken approximately on the line 5-5 15 which is provided with a plurality of work reof Fig. 1, showing the work carrier in position ceiving pockets simultaneously to grip the ground during the grinding operation;

piece of work and a new piece of work and auto- Fig. 6 is a similar view, showing the work carmatically and simultaneously to shift the ground rier movedforward to grip a new work piece and piece of work to a discharge chute and the new the work piece which has been finish ground; 20 piece of work into alignment with the work sup- Fig. '7 is a similar sectional view through the porting spindles. work loading mechanism, showing the work car- A further object of the invention is to provide rier tipped to swing the ground piece of work into a work loading device in which a work carrying a discharge position and simultaneously to carry head or member is moved horizontally into posia new piece of work into alignment with the work 25 tion to grip a ground piece of work supported on spindles;

the driving spindles and a new piece of work sup- Fig. 8 is a similar cross sectional view through ported in a hopper and simultaneously to rock the work'loading mechanism showing the work the carrier to transfer the ground piece of work carrier withdrawn to discharge a ground work to a discharge position while the new piece of piece in the discharge chute after the spindles 30 work is transferred from the hopper into alignhave gripped the. work piece;

ment with the work supporting member. A fur- Fig. 9is a detail view,, an enlarged scale, of ther object of the invention is to provide a hythe y t p W c 1 draulically actuated work loading mechanism in F 1 1s a fragmentary cr -Vi w,

which the work carrying element is hydraulically on a enlarged s a taken a p a v n t e so moved first ina horizontal direction to grip a line III-l9 0f ground piece of work and a new pieceof work Fi 11 i a fr m n ry l n i inal section.

and then is hydraulically rocked to swing the caron an enlarged scale, taken approximately. on the rier and thereby simultaneously to transfer the line of ground piece of work from the spindles to a dis- 12 is a cross Sectional View, taken DD T K 4o mately on the line l2--l2 0f Fig. 11;

Fig. 13 is a fragmentary cross sectional view, taken approximately on the line I 3-13 of Fig. 11;

charge position and the new piece of work from the hopper into alignment with the work supportg fgzy f s will be in part obvious or in part Fig. 14 is a fragmentary cross sectional view,

. taken approximately on the line M-i4 of Fig. 5;

m hereinafter: Fig. 15 is a right-hand end elevation of the The invention accordingly consists in the fearight hand work head on an enlarged scale tures of construction, combinations of elements, taken approximately on'the line of Fig and arrangements of -1 as will be exemplified Fig. 16 is a rear view of the work loading mechin the structure to be hereinafter described, and anism, taken approximately on the line |6 |6 of 50 the scope of the application of which will be indi- Fig 5; and cated in the following clalms- Fig. 17 is a horizontal sectional view, taken ap- In the H O D Y drawings in Which is proximately on the line iI-JT of Fig. 16. shown one of various possible embodiments of A full automatic grinding machine has been the mechanical features of this invention, illustrated in the drawings comprising a base 20 55 which supports a longitudinally adjustable table 2| on the usual flat way 22 and V way 23. To facilitate longitudinal adjustment of the table 2| relative to the base 26, the table 2| is provided with a depending rack bar 24 which meshes with a gear 25 (Figs. 1 and 10) mounted on the inner end of a rotatable shaft 26 which is journaled in a bearing 21 fixedly supported on the base 20. The outer end of-the shaft 26 is provided with a squared-off portion 28 which is adapted to be engaged by a removable lever 29 so that the table may be adjusted longitudinally in setting-up the machine for a given operation.

The base 20 also supports a transversely movable grinding wheel slide 32 which is supported on the usual V and fiat ways to permit a transverse adjustment of the slide relative to the base. The slide 32 supports a rotatable wheel spindle 33 which in turn supports a rotatable grinding wheel 34. The grinding wheel spindle 33 may be rotated in any convenient manner such as, for example an overhead drive or a motor drive, such as an electric motor 35 mounted on the upper surface of the wheel slide 32. The motor 35 is provided with a driving pulley 36 which is preferably of a multiple V groove type and is arranged to transmit power by means of multiple V belts 31 to a multiple V groove pulley 38 mounted on the end of the wheel spindle 33 to rotate the grinding wheel 34 for a grinding operation.

The wheel slide 32 isarranged for a transverse feeding movement either manually for adjustment or setting-up of the machine, or automatically during the automatic cycle of operation thereof. The wheel slide 32 is provided with a depending half nut 46 which meshes with or engages a rotatable feed screw 4| journaled in a slidably mounted bearing 42 at one end and a bearing (not shown) at the other end. The forward end of the feed screw 4| is slidably keyed by means of a sleeve to the inner end of a rotatable shaft 43. The shaft 43 projects from the front of the machine base and is provided on its outer end with a gear 44 which meshes with a gear 45 supported on a shaft 46. A manually operable feed wheel 41 is also supported on the shaft 46 and is either formed integral with or fixedly mounted on the gear 45 so that rotation of the manually operable feed wheel 41 is transmitted through the gear 45 and the-gear 44 to rotate the shaft 43 and thereby rotate the feed screw 4| in either direction to adjust the position of the wheel slide 32 as desired.

A pivotally mounted stop pawl 48 supported by a stud 49 is arranged to engage an abutment (not shown) positively to limit the infeed adjustment by the feed wheel 41. Associated with the feed wheel 41 is a micrometer adjusting mechanism 59 by means of which the abutment carried thereby may be precisely adjusted relatively to the feed wheel 41. This feed mechanism has not been illustrated in detail since it is not considered part of the present invention. For a more detailed disclosure of this feed mechanism, reference may be had to the expired United States patent to Norton No. 762,838 dated June 14, 1904 which discloses substantially the same type of feeding mechanism.

In order that the wheel slide 32 may be moyed rapidly toward the work piece to grind the same automatically bythe plunge-cut method, the feed screw 4| is connected through the bearing 42 with a piston rod 55. A fluid pressure cylinder 53 is arranged in axial alignment with the feed screw 4| and contains a slidably mounted piston 54 which is connected with the piston rod 55. A fluid pressure pump 59 which is driven by an electric motor or other suitable power drive serves to pump fluid through a pipe 60 from a reservoir 6| within the base 28. The pump 59 forces fluid under pressure through a pipe 62 to a main control or feed control valve 58. The main control valve 58 is'preferably of a piston type comprising a valve stem 63 and a plurality of spaced pistons which form valve chambers 64,

65 and 66 therebetween. In the position of the valve 58 (Fig. 2), fluid under pressure enters the valve chamber 65 and passes out through a passage 61 into a cylinder chamber 51 to cause the piston 54 to move rapidly toward the left (Fig. 2) 'to cause an infeeding movement of the wheel slide 32 and the grinding wheel 34. During the passage of fluid under pressure into the cylinder chamber 51, fluid is exhausted from a cylinder chamber 56, through a passage 68, into the valve chamber 66, and out through a pipe 69 which exhausts into the reservoir 6|.

The valve stem 63 is held in a forward feeding position (Fig. 2) by means of an electric solenoid 15 which is connected by a link 16 and a stud 11 to the lower end of a pivotally mounted lever 18 supported on a stud 19. The upper end of the lever 18 is connected by a pin or stud 80 with a spool shaped member 8| mounted on the outer end of the valve stem 63. When the solenoid 15 is energized, the valve 58 is held in position illustrated in Fig.2. When the solenoid 15 is deen-- ergized, the released compression of a spring 82 within the end of the valve casing serves to move the valve 58 quickly toward the right (Fig. 2) to reverse the position of the valve and to reverse the flow of fluid to and from the chambers 56 and 51 of the cylinder 53. The electrical apparatus for controlling the solenoid 15 will be described hereinafter.

Dash pot The piston 54 and cylinder 53 mechanism, above described, serves to cause the grinding wheel 34 rapidly to approach or recede from the work piece. In order to reduce the rapid approaching movement to a predetermined grinding feed, it is desirable to provide a wheel feed regulator or controlling mechanism, such as adash pot mechanism, which may be rendered effective when the grinding wheel 34 is about to contact with the surface of the work piece being ground. As illustrated in Fig. 2, an outwardly projecting casing 85 is fixed to the head of the cylinder 53 and contains a pair of diametrically spaced dash pot pistons 86 and 81. The dash pot pistons 86 and 81 normally are held in a rearward position by springs 88 and 89 respectively. During the rapid approach of the grinding wheel 34, the dash pot pistons are inoperative.

The piston rod 55 extends toward the rear of the machine and is provided at its outer end with a sleeve 9| which may be adjusted longitudinally on a threaded portion 92 on the piston rod 55 and locked in adjusted position thereon by a lock nut 93. The parts are 50 arranged that the sleeve 9| moves rearwardly when the piston rod The continued movement of the piston 54 toward 88 and 81, respectively, which forces fluid under pressure from the dash pot chambers 91 and 98 into a reservoir 99. The dash pot chambers 91 and 98 are preferably interconnected with each other by the groove I02 and are arranged to exhaust fluid therefrom either through a needle valve I00 or an adjustable throttle valve IOI into the reservoir 99. The throttle valve II'II preferably is located on front of the machine Fig. 1.

Positive stop In order to grind a work piece to a predetermined size, it is necessary to feed the grinding wheel 34 toward the work piece to grind the same and then to stop the infe'ed and allow the grinding wheel 34 to grind out or to allow the sparks to die out in order to round up the work so that it will be ground to a true cylindrical surface of a predetermined size. As illustrated in Fig. 2, the forward movement of the piston rod 55 causes a rapid approach until the sleeve 9I picks up the dash pot pistons 88 and 81 to cause a slow infeed which continues until. an adjustable sleeve I04 engages a fixed surface I05 on the rear of the casing 85, thereby positively limiting the infeeding movement of the grinding wheel 34 and causing the wheel to dwell in contact with the work during the finish grinding period. The adjustable stop sleeve I04 surrounds the sleeve 9I and is held in adjusted position thereon by means of lock nuts I08.

The throttle valve' IN is connected by a pipe I08 with the reservoir 99. The pipe I08 also connects the reservoir 99 to a ball check valve I09 which remains closed during the forward feeding movement of the grinding wheel but which is opened upon the rearward movement of the grinding wheel 34 as the dash pot pistons 88 and 81 move to a rearward position to allow quick return of fluid to the dash pot chambers 91 and 98, respectively.

The dash pot mechanism is normally an independent fluid mechanism during the normal operation of the machine. In order readily to fill the reservoir 99 to maintain the desired quantity of fluid therein, a pipe H0 is connected be tween the pump 59 and reservoir 99. A valve III is located in the pipe IIO to control the flow of fluid through the pipe IIO. An overflow pipe H2 is connected between the vertically extending portion of the reservoir 99 and the main reservoir 8I within the base '20 of the machine so that in case the fluid within the reservoir 99 rises above a desired level, the excess fiuid will return directly to the reservoir within the base of the machine. Ordinarily the valve III is merely opened when it is desired to fill the reservoir 99 and then remains closed during the normal operation of the machine. If desired, however, in order to insure the fluid level within the reservoir 99 at all times, the valve III may be opened partially so that there will be a continuous flow of fluid into the reservoir 99, and in this case the overflow pipe II2 serves to prevent the fluid level rising above the desired point.

Work supporting and rotating mechanism In order to grind the entire peripheral surface of a work piece automatically, it is desirable to provide means for supporting and driving the opposite ends of the work piece to center and support the work piece as well as to rotate it during the grinding operation. In the construction illustrated, a pair of spaced work supporting heads H5 and H8 are mounted on a swivel table II9 which is provided on the work supporting table 2I. The work heads H5 and H8 rotatably support a pair of aligned work supporting androtating spindles H1 and H8, respectively.

The table 2I is provided with the usual swivel table II9 which is arranged to pivot on a central stud I20 set in the table 2I and projecting into a corresponding shaped aperture I2I in the swivel table H9. The upper surface of the swivel table I I9 is formed with a dovetailed surface I22. The work head I I5 is provided with a dovetailed surface I23 which mates with the surface I22 on the swivel table II9. A clamping block I24 held in position on the work head II5'by a clamping screw I25 serves securely to lock the head H5 in position thereon. Similarly, the head I I8 is provided with a dovetailed surface I28 which mates v with the surface on the swivel table H9, and a clamping block I21 and clamping screw I28 securely clamp the work head H8 in position on the swivel table H9.

The spindles H1 and H8 are provided with a suitable driving mechanism so that they may be rotated in synchronism with each other so as to provide a uniform timed driving of opposite ends of the work piece. In the construction illustrated an electric motor I34 is mounted on the left-hand end of the swivel table H9. The motor I34 is provided with a motor shaft I35 connected by a coupling I38 with a rotatable shaft I31 journaled in bearings I38 and I39 in the head H5. The shaft I31 carries at its inner end a gear 'I40 which meshes with a gear I mounted on the end of a rotatable shaft I42. One end of the rotatable shaft I42 is journaled in a bearing I43 in the head H5 and the other end of the shaft I42 is journaled in a bearing I44 in the head H8. The shaft I42 is connected to simultaneously rotate the spindles H1 and 8,.

respectively. A sprocket I45 is keyed on the left-hand end of the shaft I42 (Fig. 4) and is connected with a sprocket I48 on the work spindie I I1 by means of a link chain I41. An adjustably mounted idler sprocket I48 serves to take up any lost motion in the chain I41 and to main-- spindles H1 and H8 may be rotated in synchronism with each other.

It isdesirable to provide a suitable adjustment in the driving mechanism so that the two spindles having specially shaped work supporting and driving centers may be timed accurately with each other and thereafter rotated in absolute synchronism with each other. To accomplish thisresult, the sprocket I50 is not fixed to the shaft I42 but is rotatably supported thereon. A plate I is mounted on and fixed to a hub projecting from the sprocket I50. The plate I55 is mounted on and fixed to a hub projecting from the sprocket I50. The plate I55 supports a driving stud I58 which is arranged to drive a plate I51 which is fixedly fastened to the end of the drive shaft I42. The plate I51 is provided with a cut-out. portion I58 which is of sufficient size and width to allow freedom of movement and adjustment of the stud I58 carried by the plate I55. The cut-out portion I58 provides a pair of opposed adjusting screws I6I and I62 which are carried by the projections I59 and I60, respectively, on the plate I57 and serve to engage opposite sides of a squared end portion of the stud I56. By slacking OH on one of the screws I 6| or I62 and tightening the other screw, the plate I55 may be adjusted angularly relative to the plate I57 so as to time the work supporting spindle I I8 in the desired relationship with the work supporting spindle I I7.

In order to clamp or lock the plates I55 and I57 in adjusted position, a pair of clamping screws I63 and I64 are provided. These screws pass through elongated slots I65, I66 in the plates I57 and are screw threaded into the plate I55 so that the two plates may be rigidly locked in adjusted position when desired, thus permitting timing of the work spindles.

Work spindles The two aligned opposed work supporting heads H5 and IIS are substantially identical in construction, the only difference being that one is a right-hand and the other a left-hand head. Consequently, only one oi these heads has been shown in detail in cross section. It should be understood, therefore, that the right-hand head (Fig. 3) is identical in construction and description with that described and illustrated inconnection with the left-hand head. A collar III) is threaded onto the end of the spindle II I and contains a plurality of springs III which are arranged automatically to apply a tension to the parts of the anti-friction ball bearings I38 and IBI so that lost motion between the bearing parts is taken up at all times during the operation of the machine.

For convenience of assembly and manufacture. "the spindle M7 is formed in two parts comprising the outer part Ill and an inner sleeve I72 which has a flange IE3 engaging a correspondingly shaped aperture in the spindle III. The other end of the sleeve I72 is threaded and a collar I78 fitted thereon serves to lock the spindle III and sleeve I72 so that they rotate together. 'A sleeve I85 is slidably keyed within the sleeve I72 by means of a'key I76. The outer end of the sleeve I75 is provided with a tapered aperture adapted to receive the tapered portion of a work supporting and driving center I'M. A sleeve I78 within the sleeve I75 serves to locate a spring I79. The spring I79 is located between a flange on the sleeve I78 and a collar I80 which is screw threaded within the sleeve I72. The compression of the spring I79 serves normally to hold the work supporting and driving center I77 and its supporting slfieve H5 toward the right (Fig. 3) into a driving position, as illustrated therein.

A fluid pressure cylinder '85 is formed either integral or fixedly mounted on the end of the work head H5. The cylinder I contains a piston I86 which is slidably mounted therein and is normally held in a position toward the right, (Fig. 3) by two springs I87 to aid in moving and holding the work supporting center I77 in a direction toward the right to support and drive a work piece I88 having a plurality of broached splines therein.

To retract the center I77, fluid under pressure may be admitted to a cylinder chamber I89 within the cylinder I85, which serves to cause the sleeve I75 to be moved toward the left (Fig. 3) against the compression of the spring I79. I

The piston I86-is pre erably connected with the sleeve I78. by a lost motion connection, such piece I88 by means of the spring I79.

as by means of a flange I90 which is provided with an integral hub I 9| that is connected to the sleeve I78 by a screw I92 havinga cylindrical end portion thereon engaging an elongated slot in the sleeve I78. The flange I90 is positioned within a recessed portion I93 in the left-hand end of the piston I86 and is located between the bottom of the recess I93 and a plate I94 which is fastened on the end of the piston I86. A collar I95 is fastened on the end of the sleeve I78 by means of a screw I96. The collar I95 is provided with an adjusting screw I97 which is arranged parallel with the sleeve I78 and which serves to adjust the amount of lost motion between the piston I86 and the flange I90. The piston I86 is arranged "so that the sleeve I78 rotates therewithin and the lost motion connection between the piston and the sleeve I78 serves to allow the spindle to be rotated and the sleeve I78 to rotate freely without any friction between the flange I90 and the piston I86. The springs I87 serve normally to hold the piston I86 in the position illustrated in Fig. 4, that is in a position toward the right, bearing against a thrust collar I98 which is fixedly mounted within and at one end of the cylinder I85.

It will be readily apparent from the foregoing disclosure that the slidably mounted sleeve I75 within the work supporting spindle I I7 is normally held in a position toward the right, that is, in

operative position to support and drive a work The piston I86 is normally held in a position toward the right against the flanged portion I98 at the end of the cylinder I 85 by means of the springs I8'I. When it is desired to retract the center after a work piece I88 has been ground, fluid under pressure is admitted to the cylinder chamber I89 to move the piston I86 toward the left against the compression of the springs I87 and L to retract the sleeve I75 toward the left against the compression of the spring I79 to withdraw the work supporting and rotating center I77 to an inoperative position. The fluid pressure system for controlling the admission of fluid to the cylinder I85 will be hereinafter described.

Similarly, the right-hand head H6 (Fig. 3) is provided with a spindle and sleeve construction identical with that above described in connection with the left-hand head -H5. The right-hand head H6 is provided with a cylinder 200 having a piston 20I slidably mounted therein. The piston 20I is normally held in the position illustrated in Fig. 3, up against a flange or thrust plate 202 (Fig. 4), fixed to the inner end of the cylinder 200, by means of two springs 203. A lost motion connection is provided to connect the piston 20I to a sleeve 204 within the spindle II8. This lost motion connection comprises a flange 205 having a hub 206 formed integral therewith. The flange 205 is located within a recess 207 within the piston 20I and the flange 205 is located between the bottom of the recess 207 and a plate 208 partially covering the end of the recess 207. The hub 206 is provided with a screw 209 which has an inwardly projecting portion sliding within an elongated slot in the sleeve 204. A collar 2I0 is fixedly mounted on the end of the sleeve 204 by means of a screw 2H and is provided with an adjusting screw 2I2 arranged to engage the flange 205 and adjust the position of the flange 205 relative to the sleeve 204 and thereby adjust the amount of lost motion between the flange 205 and the piston 20I.

The spindle H8 is provided with an inner longitudinally slidable sleeve 2I3 similar to the sleeve I15 in the work head II5, which in turn supports a work supporting and rotating center 2I4 similar to the center I 11. The spindle IIB has anti-friction ball bearings I32 and I33, similar to bearings I38 and I3I in the work head H5, and the take-up for lost motion is the same.

Since both of the work supporting centers I11 and 2I4 are arranged for endwise movement toward and from each other to grip and release a work piece I88 which is held thereon and therebetween for a grinding operation, it is desirable to provide suitable elements which may serve both to locate the work piece I88 in a predetermined position with relation to the grinding wheel 34 and which also may serve as strippers to hold the Work piece I88 against endwise movement during the withdrawal of the work centers I11 and 2I4. A sleeve 2 I surrounds the slidable center supporting sleeve 2 I3 on the work head I I6. A flange 2I6 is formed integral with the sleeve, 2I5 and is fixedly secured to rotate with the spindle I I8. The end face of the sleeve 2I5 serves to locate the right-hand end of the work piece I88 when gripped between the supporting centers I11 and 2I4.

In order to compensate for any slight variations in the length of successive work pieces I88, a sleeve 2I1 surrounds the longitudinally adjustable sleeve I15 of the work head I I5. The sleeve H1 is any slight variations in length of successive work pieces I88, a second sleeve 2I9 is slidably mountcd within the sleeve 2" and is normally urged toward the right (Fig. 4) by means of equally spaced springs 220. A plurality of balls 22I arranged in spaced relationship are interposed between the sleeves 2I1 and 2I9 to allow the inner sleeve 2I9 to slide freely therewithin and also serve to drive the sleeve 2I9 with the sleeve 2". A band 222 mounted in a recess in the sleeve 2I1 maintains the balls MI in driving position. The end face of the sleeve 2I9 engages the left-hand end of the work piece I88 (Figs. 4 and 11) and serves when the sleeves I15 and 2I3 are moved toward each other to grip a work piece I88 to move the work piece endwise so that its righthand end engages the end of the sleeve 2I5. Due to the springs 228, the sleeve 2I9 may yield relative to the sleeve 2I1 to compensate for any slight variations in the length of successive work pieces I88.

The sleeves 2 I5 and 2 I 9 also serve as strippers to hold the work piece I88 against endwise motion when the sleeves I 15 and 2I3 are withdrawn to release a ground piece of work I88.

In order to hold the work supporting centers I11 and 2I4 in position within the sleeves I15 and 2I3, a rod 223 having a head 224 extends within the sleeve I18 and is screw threaded into the tapered portion of the center I11 so as to lock the center I11 in a definite operating position.

Similarly. a rod 225 having a head 226 extends through the sleeve 204 and is screw threaded into the center 2I4 to lock the same in an operative position within the sleeve 2I3.

Work magazine or hopper then moved to shift the ground piece of work to a discharge position while moving the unground piece of work into alignment with the center, thereby unloading and loading the machine in a single movement of the work carrier or loader.

In the construction illustrated, a work hopp r or magazine 221- carrying a plurality of unground pieces of work I88 is supported by the bracket 228 fixed to the work supporting heads H5 and H6 (Figs. 5 and 17). The outer end of the work discharge chute 221 is similarly supported by an inverted V shaped supporting frame 229 which is adjustably connected to a bracket 230 which connects the heads H5 and H6. The frame 229 is provided with elongated slotsthrough which clamping bolts pass and which are arranged to clamp the frame 229 in adjusted position on the supporting bracket 230. By adjusting the frame 229 vertically, the angular position of the work magazine or hopper 221 may be varied as desired so that the successive work pieces I88 will roll in succession into an operating position. The bracket 230 which connects the outer ends of the heads H5 and H6 is provided with an inwardly extending boss 23I (Figs. 3 and 5) which serves as a support for a pivot shaft 232 which passes through an aperture within the boss 23I and is held in adjusted position therein by means of a set screw 233.

A work carrier frame 235 is provided with a pair of spaced downwardly extending arms '235 (Fig. 1) which have enlarged hubs 231 and 238, respectively,'at their lower ends, each of which is provided with a bushing or bearing member 239 and 240, respectively, which are pivotally supported on the non-rotatable shaft 232 and serve to permit the work carrier frame 235' to be rocked about the shaft 232 as an axis.

The work carrier frame 235 is provided with a longitudinally extending fluid pressure cylinder 245. A piston 246 is slidably mounted within the cylinder 245. -A piston rod 241 is formed integral with the piston 246 and passes through a cylinder head 248 having a fluid tight packing, which serves as a bearing support for the piston rod 241. A circular slide cover 249 is fastened on the outwardly projecting end of the piston rod 241 by means of a nut 250 threaded onto the end of the piston rod. A work carrier head 25I is fixedly mounted on the slide cover 249 so as to move therewith. The work carrier head 25I is provided with a pair of spaced plates 254 and 255 (Fig. 16) having spaced pockets 252 and 253 formed therein which are of a diameter substantially equal to the piece of work I88 to be ground and are spaced apart by a distance substantially equal to the spacing between the piece of work I88a in the lower portion of the hopper 221 and the work piece I88, which is mounted on the centers I11 and 2M and has been ground to a predetermined size. I

In order to maintain the work carrying hea 25I and its associated parts in a vertical position during the movement of the piston 246, 'a slide block 243 is fixedly attached to a slide cover 249 which surrounds the cylinder head 248. The slide block 243 is slidably supported on a cylindrical surface on the front end of the work carrier frame 235 and the cylinder head 248. The slide block 243 and the slabbed-off surface 244 on the frame 235 serve as a guide to maintain the work carrying head 25! in an operating position and prevent rotation thereof with the piston 246.

A pair of pivotally mounted spring actuating fingers 256 and 251 are provided on the work carrying head 25I which serve to hold a work piece I88 within the pockets 252 and 253 during the transfer movement from the magazine or hopper 221 to the work centers I11 and 2M and from the work centersto the discharge chute. The fingers 256 and 251 are pivotally mounted on the upper part of the plates 254 and 255 of the work carrier head 25l by means of studs 258 ground work piece I88 within the pockets 253 so as to transfer it to a discharge position.

The finger 256 is normally held in the position illustrated in Fig. 5 by means of a spring 265 which is connected between a stud 266 carried by the plate 254 and a stud 261 mounted on the finger 256. An adjustable stop screw 268 carried by the finger 256 together with a stop pin 269 mounted on the work carrier head 25l serves to limit the movement of the finger 256 in a counterclockwise direction.

The finger 251 is held in a similar position by means of a spring 212 which is fastened at one end to a stud 213 carried by the plate 255 and fastened at its other end to a stud 214 on the finger 251. An adjustable stop screw 215 carried by the finger 251 and a stop pin 216 serve normally to hold the finger 251 in position to support a work piece I88 in the pocket 252. The tension'of the springs 265 and 212 is sufficient to hold a work piece I88 in the pocket 252 when the work carrier head 25I is moved forward and to withdraw the same from the hopper 221 when the work carrier 25I is swung' to discharge aground piece I88 and present a new piece of work I88a into alignment with the work centers I11 and 2.

The fingers 269 and 26 I are similarly arranged,

each having a spring 218 interposed between Studs 219 on the plates 254 and 255 and a stud 289 on the upper surface of each of the fingers 269 and 261 normally tending to holdthe fingers in the position illustrated in Fig. 5, with the adjustable stop screw 28l in engagement with a stop pin 282 carried by the plates 254 and 255.

The hopper 221, as illustrated, comprises a trough of a box-like cross sectional area having a portion of the top out out. The inner crosssectional area of the carrier is of sufficient size to allow a'free rolling movement of the work pieces I88 as they are placed in the machine. The outer portion of the hopper 221 is arranged in an inclined manner so that the work pieces will roll toward the discharge end of the hopper. The first work piece I88a in the hopper 221 rests on a surface 285 at the lower end of the hopper 221 and is held in position therein by a pair of spaced pivotally mounted arms 286 and 281 which are pivotally mounted on studs 288 and 289, respectively (Fig. 16) The lower end of each arm 286 and 281 is provided with a screw 299 and 29I respectively, which project inwardly toward each other. The heads of the 299 and 29I screws serve to bear against the work piece I88a to hold the same within the hopper 221 until it is gripped and transferred therefrom by the forward and downward movement of the work carrying head 25L A spring 292 is interposed between the upperv end of the lever 286 and a portion of the bracket 228 supporting the hopper 221 and serves normally to hold the lever 286 in the position illustrated in Fig. 5, with the head of the screw 299 engaging the work piece l88a. An adjustable stop screw 293 serves to limit the rocking movement of the lever 286 in a clockwise direction (Fig. 5) and similarly an adjustable stop screw 294 serves to limit the rocking movement of the arm 286 in a counterclockwise direction. The arm 28 1 is similarly mounted, so that a spring 295 normally rocks the lever 281 in a counterclockwise direction (Fig. 3) to maintain the screw 29I in position to support the work piece I88a in position with the work carrier pockets 252. An adjustable stop screw 296 carried by the lever 281 serves to limit the rocking movement of the lever in a counterclockwise direction, Fig. 3. Similarly, a stop screw 291 carried by the lever 281 serves to limit the rocking movement of the lever 281 under the influence of the spring 295 in a clockwise direction (Fig. 3). It will thus be seen that by means of the spring actuated, pivotally mounted levers 286 and 281, the heads of the screws 299 and 291 engaging the lower workpiece I88a in the hopper 221 serve to retain the work piece in this position until the same is grasped by the pockets 252 on the forward movement of the work carrier head 25I.

The work carrier head and associated parts, as shown in Fig. 5, are in a grinding position, that is the grinding wheel 34is in engagement with the work I 88 and the work is ground substantially to size. After completion of grinding on the work piece I88, the work carrier head 25I is preferably moved in a substantially horizontal plane so that the pockets 252 grip the work piece |88a and the pockets 253 grip the ground work piece I68. The work carrier 25I and its associated parts are moved forward to grip the groundwork piece I88, as shown in Fig. 6. The work carrier head 25l and" associated parts are then rocked about the shaft 232 as a pivot to swing the finished ground work piece I 88 into position l89b (Fig. 7), in alignment with the upper end of a discharge chute 399 and at the same time swings the work piece I88a into position I 88 in alignment with the work supporting and rotating centers I11 and 2. The work carrier 25I and its associated parts, while in a tilted position, are then withdrawn from the position shown in Fig. 7. As the work carrier head 25I recedes from the position in Fig. 7, a pair of ,lugs 391 and 392 on the discharge chute 399 engage the ground work piece I88!) and hold it in the upper end of the discharge chute as the work head 25I recedes from the work. During this movement,

the gripping fingers 269 and 26l are rocked about their studs 262 and 263 to release the work piece |88b from the pockets 253 into the discharge chute 399 whereupon the finished ground work piece I88 rolls by gravity to the pan 393 carried by the table 2| on the front of the machine. Excess coolant fluid is exhausted through the flexible hose 394 into the coolant reservoir in the base 29 of the machine.

Similarly, before the work carrier 25I starts its rearward movement, that is, toward the left (Fig. 7), the work gripping centers I11 and 2 have gripped the work piece I88 and the withdrawal movement of the work carrier head 25I rocks the fingers 256 and 251 to withdraw the pockets 252 from engagement with the new piece of work I88 to be ground. The work carrier head 25I and its associated parts then assume the position illustrated in Fig. 8, after which the work carrier 25I and parts are rocked in a counterclockwise direction to return into the normal position of the parts, as shown in Fig. 5, ready for the next cycle of movement thereof.

The movement of the work carrier 25I simultaneously to. pick up a new piece of work I88a to be ground and the piece of work I88 whichhas been ground and simultaneously to shift them into an operating position and a discharge position, respectively, serves to reduce the idle movement and thereby increase the production and efllciency of the machine. The movement of the work carrier head 25I is preferably hydraulically actuated by means of a pair of pistons and cylinders, one of which moves the work carrier in a horizontal position and the other of which serves to rock the work carrier to transfer the work pieces, as above described. These two cylinders and pistons are interconnected so that they operate in timedrelation with each other.

In the position of parts as shown in the dia gram in Fig. 2, fluid under pressure, from the pump 59, passes through the pipe 62 into the chamber 65 of the valve 58 and passes out through a pipe 385, a section of which is flexible hose to allow free rocking of the work carrier frame 235, through a passage 386 in a valve 381, through a pipe 383 and'a valve 389 and a pipe or passage 3I8, into a cylinder chamber 3 within the cylinder 245 to move the piston 246 together with the piston rod 241 and plate 248 carrying the work carrying head 25I toward the left, (Figs. 2 and 5) to, withdraw the work carrying head 25I into its rearward or inoperative position as shown. During the movement of the piston 246 toward the left, fluid withina cylinder chamber 3| 2 exhausts through a pipe or passage 3I3 and a valve chamber 314 in the valve 381 and passes I through a pipe 3I5, a section of which is flexible hose to allow freerocking of the work carrier frame 235 to the valve chamber 66 in the valve- 56 and through the exhaust pipe 69 into the reservoir 6|.

The valve 389 is adjusted to regulate the load- ,work centers to the discharge chute 388, a fluid pressure cylinder 3I6 is fixedly mounted on the outer end of the work carrier frame 235 and is arranged in a substantially vertical position, at right angles to the cylinder 245. The cylinder 3I6 contains a piston 3| 1 which is connected by a piston rod 3I8 and a grooved spool shaped member 3I9 with a pair of opposed shoes 328 and MI which engage the groove in the spool shaped member 3I9 and are pivotally supported by trunnions 322 and 323 on the bracket 238.

Fluid under pressure entering the cylinder chamber 3 passes through a passage 324 into a cylinder chamber 325, which serves to produce a downward movement of the cylinder 3I6 and the work carrier frame 235, the piston 3" being held fixed to the bracket 238 to swing the work carrying frame 235 from the position illustrated in Fig. 8' into the position illustrated'in Figs. 2

and 5. During the downward movement of the cylinder 3I6, fluid is exhausted from a cylinder" chamber 326, through a pipe or passage 321, through radially extending holes 328 in the cylinder 245 and through longitudinally arranged mains in the position illustratedin full lines in Fig. 2, except when it is desired to set up the work carrying head 25I and its associated mechanism when the same may be manually operated to move the work carrying head 25I independent of the other mechanisms of the machine.

When the wheel feed control valve 58 is shifted into its reverse position, the direction of flow of fluid under pressure to the cylinder 245 is changed so that fluid under pressure passes through the pipe 3I3 into the cylinder chamber 3I2 to cause the piston 246 to move'toward the right (Figs. 2 and 5) so as to move the work carrying head 25I into the position illustrated in Fig. 6. The fluid in the cylinder chamber 325 is exhausted through the passage 324 into the radially extending holes 332 in the cylinder 245 through the longitudinally equally spaced holes 333 which extends to the continuous groove, and connects 2I4. As soon as the work centers have gripped the work I88, as hereinafter described, the feed valve 58 is again shifted, by energizing the solenoid 15, into the position illustrated in Fig. 2, in which position fluidunder pressure causes a rearward movement of the work carrying head 25I intothe position illustrated in Fig. 8, after which fluid is admitted to the cylinder chamber 325 again to rock the work carrier head 25I into the position illustrated in Figs. 2 and 5.

Electrical control and interlock In a machine of this type, it is desirable to provide suitable interlocks between the various mechanisms of the machineto insure safe operaticn thereof, without endangering the-operator or damaging the work pieces I88 passing therethrough. It is desirable to provide an electrical interlock between the work gripping centers I11 and 2I4 and the wheel fccd control valve 58 so that the solenoid 15 cannot be energized-unless boih of the work gripping centers are in an operative position in engagement with the work piece I88 to be ground. The mechanisms of the machine, as shown diagrammatically in Fig. 2, are in a grinding position. The trip switch 336 is normally held in a closed position by means of a spring 331. An actuating plunger 338 is arranged in the path of an adjustable screw 339 carried by a pivotally mounted lever 348 mounted on a stud 34I fixed to the end of the cylinder I85 of the work head II5. A rod 342 is fixed to the piston I86 and projects through an aperture within the end cover of the cylinder I85 and is arranged to engage the lever 348. A spring 343 having one of its ends connected to the upper end of the lever 348 and its other end connected to a stud 344 fixed to the top of the cylinder I85 serves normally to maintain the lever 348 in engagement with the rod 342. of the parts shown, Fig. 2, the switch 336 is closed. When fluid under pressure is admitted to the cylinder chamber I89 to cause the piston I86 to move toward the left to withdraw the work centers I11 and 2I4 to an inoperative position, the rod342 rocks the lever 348 in a counter-clockwise direction, which serves to move the switch actuating plunger 338 toward the left,

Fig. 2, to trip the switch 336 and thereby break the circuit.

A similar safety connection including a normally closed trip switch 345 is normally held in a closed position by means of a spring 346. An actuating plunger 341 is arranged in the path of V an adjustable screw 348 carried by a pivotally mounted lever 349 mounted on a stud 358 fixed to the end of the cylinder 288 of the work head II6. A rod 35I is fixed to the piston 28I and projects through an aperture within the end cover of the cylinder 280 and is arranged to" en-,

-the parts shown in Fig. 2, the switch 345 is closed. When fluid under pressure is admitted to the cylinder chamber 2I2 to cause the piston 2III to move toward the right (Fig. 2) to withdraw the work center 2I4 to an inoperative position, the rod 35I rocks the lever 349 in a clockwise direction which serves to move the switch actuating plunger 341 toward the right (Fig. 2) to trip the switch 345 and' thereby break the circuit.

A similar trip switch 368 is operatively connected to be actuated by a cycle timing valve to be hereinafter described. The switch 368 is normally held in an open position by means of a spring 36I and is provided with an actuating plunger 362 which is arranged in the path of an adjustable screw 363 which is mounted in the upper end of a rock arm 364. The rock arm 364 1 inder. 368.

Cycle timing piston and cylinder The cycle timing piston and cylinder serves to control the admission of fluid under pressure to the work head actuating cylinders in timed relation with the other mechanisms ofthe machine.

The piston 361 is normally held in a right-hand position (Fig. 2) by means of a pair of springs '369 and 318 which are connected between studs 3" and 312, respectively, on the cylinder cas- In the position ing and the other ends of which are fastened to studs 313 and 314 on the rock arm 364. These springs normally tend to rock the rock arm 364 in a counterclockwise direction. A cylinder chamber 315 within the valve 368 is connected by a pipe 316 with a passage 311 in a cycle timing valve 318. The passage 311 is connected by a ball check valve 319 with a passage 388 which enters a valve chamber 38I within the piston type cycle timing valve 318.

The pipe 316 leading from the cycle timing piston and cylinder 368 also connects with a pipe 382 which in turn is connected with an exhaust I pipe 383 to exhaust fluid into the reservoir 6I. A valve 384 is located in the pipe line 382 and serves to close off the exhaust from the cycle timing valve when desired in setting up the machine for grinding a given work piece I88. An adjustable throttle valve 385 is also located in the pipe line 382 and serves to adjust and control the rate of exhaust from the cycle timing piston and cylinder 368 and thereby to control the cycle of operation. Whenthe fluid is exhausted from the chamber 315 in the cycle timing piston and cylinder 368 by the piston 361, the ball check valve 319 is closed by back pressure of the fluid so as to allow fluid to exhaust only through the pipe 316 to the needle valve 385 in the pipe line 382 to exhaust through the pipe 383.

Cycle timing valve The cycle timing valve 318 is preferably a pistontype valve comprising the valve pistons 386, 381, and 388 which are formed integral with a valve stem 389, thus forming valve chambers 398, 38I, 392, and 393.

As shown in Fig. 2, fluid under pressure from the pump 59 passes through the pipe 62 and through a pipe 394 which connects with the valve 318. In the position of parts as shown, the valve piston 386 closes the port for the pipe 394. Fluid under pressure passing into the main control valve 58 passes out through a pipe 385 and through a pipe 395 and a throttle valve 396 into the valve chamber 390'to move the pilot valve to the right-hand position, as shown in Fig. 2. The valve 396 serves to control the rate of admission of fluid to the valve chamber 390 and thereby controls the rate of movement of the pilot valve. During this movement of the pilot valve, fluid within the chamber 393 exhausts through a pipe 391, an adjustable throttle valve 398 and a pipe 3 I 5 which exhausts fluid through the valve chamber 66 and returns it through the pipe 69 to the reservoir 8|. The valves 396 and 398 serve to control the rate of movement of the cycle pilot valve.

When the main control valve 58 is reversed and fluid under pressure is admitted to the pilot valve chamber 393 to shift the pilot valve 318 toward the left, fluid under pressure passing throughthe pipe 394 may enter the valve chamber 38I and pass through the passage 380, the ball check valve 319, the passage 311, the pipe 316, into thecycle timing piston and cylinder 368 to cause-the piston 361 to move toward the left, therebyrocking the rock arm 364 to move the switch plunger 362 toward the right (Fig. 2) which in turn closes the switch 368 so that the work spindles grip the next work piece, thereby closing trip switches 336 and 345, which closes the circuit and serves to energize the solenoid 15 to start the infeeding movement of the grinding wheel.

An adjustable stop screw 488 on the cycle timing valve 368 serves to limit the movement of the 48 and deenergizing the solenoid parent from the foregoing disclosure. When it is a desired to start the machine in operation, a control button 482 on the front of the-machine base is actuated to start'the wheel rotation, a push button 483 is actuated to start the fluid pump, and

a push button 404 is actuated to-f start the work drive motor I34. The push button 48I is then actuated to start the, cycle of operation. The switch MI is connected in series with the trip switches 336, 345, and 358, and serves to energize the solenoid 15 which shifts the controljvalve 58 into the position shown in Fig. 2'to start a forward feeding movement of the grinding wheel 34. Assuming a work piece to be already located on the work centers, fluid under pressure entering the valve chamber 65 passes into the pilot valve chamber 398 to shift the cycle timing valve 318 into the position illustratedin Fig. 2'. The grinding wheel 34 advances to grind the work I88 to the required size and the extent of the grinding operation, that is infeed and'dwell, is determined by the adjustment of the cycle timing piston and cylinder 368 which meters fluid from the valve chamber 315 through the variable throttle valve 385 into the exhaust. When the cycle timing piston 361 has moved toward the right a sufficient distance during the grinding operation, the trip switch 368 is opened, thereby breaking the circuit 15 which releases the compression of the spring 82 and returns the feed control valve 58 to its reverse position so that fluid under pressure is admitted through the valve chamber 88 into the cylinder chamber 58 to cause a rearward movement of the grinding wheel 34; The shifting of the feed control valve 58 admits fluid under pressure through the pipe 3I5 and the pipe 391 into pilot valve chamber 393 to start the cycle timing valve 318 moving toward the left and at the same time passes fluid through the passage 3 in valve 381 and through the pipe 3|3 into the cylinder chamber 3I2 to move the work carrying member 254 forward simultaneously to grip a; new piece of work I88a and the ground-piece of work I88,

When fluid is admitted through the pipe into the pilot valve chamber 393 to cause the tim- 'as' governed by the ing, valve .318 to move toward the, left,;' fluid is} e cylinder ham to tires to allow time for'the work centers I11 and 2 I4 to be disengagedan'd the work carrier '25I'to be and 'closed, thereby completes the the solenoid 15 to shift the feed control valve ing spindles.

v U tantaneous'ly while'the "timing valve m is beingmovedtawa'rd thedeft. 5 3 The speed oimovement ofthetiming valve- 318* "speedup the oper'ation of the carrier. x:

' The valve 4I2 is provided to facilitate independent movement of the work supporting cenv'alves 396 and 398 i's'such as rocked to remove the finished work piece I88 and present an unground work piece I88a into alignment with the work centers I11 and 2I4 before the valve piston 388 covers the port to cut off fluid from the pipe 391. When the pressure from the pipe 391 is cut off and the pipe M9 is uncovered, the released compression of the springs I81 and 283, spring I19 in the work supporting head H5, and a similar spring in the work head 8 serves rapidly to move the work spindles simultaneously toward each other to engage the work centers I11 and 2I4 with the unground work piece I88a. This movement serves rapidly to exhaust fluid from the cylinder chambers I89 and 2I2 in the cylinders I85 and 288. Any leakage of fluid by the pistons I86 and 28I is exhausted by an extension of the pipe 383 into the reservoir 6I. This movement of the spindles into an operative position serves to close the trip switches 338 345. The trip switch 388 being already circuit to energize 58, so as to move the grinding wheel 34 toward the work piece I88. At the same time pressure in the pipe 385 passes through a passage 386 in a valve 381, through a pipe 388, the valve 389 and the pipe 3I8, into a cylinder chamber 3I I, to move the work carrier 25I away from the work into the position shown in Fig. 8. The radially extending holes 328 are uncovered and at the same time the holes 332 are uncovered and fluid passes through the passage 324 to the cylinder chamber 325 to rock the work carrier head 25I into the position illustrated in Figs. 2 and 5. During the downward movement of the cylinder 3I8, fluid is exhausted from the cylinder chamber 328 through the pipe 4I8, a ball check valve in cylinder I85, and through the pipe M4, the pipe M3, the valve M2, the pipe M8 and the pipe 4I9.

During the period while the work gripping centers are separated, a pipe M8 is uncovered by movement of the piston I88 toward the left (Fig. 2) which serves to admit fluid under pressure through a; valve M1 and pipe or passage 321 into cylinder chamber 326 to move the cylinder 3I8'upwardly, thereby rocking the work carrier 25I in a clockwise direction to shift the ground piece of work I88 into a. discharge position I88b and simultaneously to move a new piece of work I88a into axial alignment with the work gripping centers.

The arrangement above described is such that the exhaust of fluid from the cylinder chamber 328 through the valve 4 is controlled in timed relation with movement of the pistons I86 and 28I which actuate thework gripping and rotat- This arrangement of parts serves to delay applying of pressure of the work carv r against, the workduringits movement to r d'p'iceof work to the discharge sh re'c off'work into-axialalign- Italso serves to elimi- I' th work *ca'rrying the vilithdra al of operation, I

alve" 428 opened. which allows'- passage of cfluid etween the cylinder chamber f'326*, 'the pipe 3 2 1 and jthpassage 328 in"the work carrierhorizontal cylinder: This connection avoids -the delayed: ac-

tion' of the Work carrying member'ian'd tends to ters in setting up and adjusting the machine elements. During the normal operation of the machine under control of the automatic cycle control mechanism, the valve H2 remains in the position illustrated in Fig. 2. If it is desired manually to operate the pistons independent of the cycle control mechanism, the valve 2 is shifted in a clockwise position into the position illustrated in dotted lines in Fig. 2 so that fluid under pressure from the pump 59 is admitted to the cylinder chambers I89 and 212, respectively, to withdraw the work supporting centers independently of the cycle control.

This cycle of operation is then continued on successive pieces of work. By manipulation of the various control valves, the timing of the movement of the various hydraulically actuated parts may be regulated as desired to obtain-the desired coordinationin the movement of the various parts of the machine.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made'in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:--

1. An automatic cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces successively to said spindles each of which is operated by a separate fluid motor, a main control valve in control of said grinding wheel fluid motor and said work carrier fluid motor, a cycle timing valve controlled thereby, said cycle timing valve being in control of said spindle fluid motor, and a cycle timing piston and cylinder to control the cycle of operation.

2. An automatic cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces to said spindles each of which is operated by a separate fluid motor, a main control valve in control of said grinding wheel and work carrier fluid motors, electrically operated means to actuate said valveto cause an infeeding movement of the grinding wheel, a cycle timing valve controlled by said valve, said cycle timing valve being in control of said spindle fluid motors, a cycle timing piston and cylinder to control the grinding cycle, and an electric switch actuated by said cycle timing cylinder to operate said electrical means to shift the main control valve and thereby cause a rearward separating movement of the grinding wheel.

3. An automatic cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axiallyaligned work supporting and rotating spindles, means synehronously to rotate said spindles, means to rotate said grinding wheel, means to move said spindles simultaneously toward and from each other to grip or release a work piece therebetween, a wheel feeding mechanism arranged to feed the grinding wheel either toward or from the work, means including an electric solenoid to actuate said feeding mechanism to initiate an infeeding movement of the grinding wheel, and an electrical interlock including trip switches actuated by the longitudinal movement of the work supporting spindles which are connected in series with said solenoid and are arranged to prevent energizing said solenoid until the work spindles are in supporting engagement with the work piece.

4. An automatic cylindrical grinding machine having a, transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces to said spindles each 01' which is operated by a separate fluid motor, a main control valve in control of said grinding wheel, an electric solenoid to actuate said valve to cause an infeeding movement of the grinding wheel, a cycle timing valve controlled by said valve, said cycle timing valve being in control of said spindle fluid motors, a cycle timing piston and cylinder to control the grinding cycle, and an electrical switch actuated by said cycle timing piston and cylinder 'to actuate said solenoid to shift the main control valve and thereby cause a rearward separating movement of the wheel.

5. An automatic cylindrical grinding 'machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, means synchronously to rotate said spindles, means to rotate said grinding wheel, means to move said spindles toward and from each other to grip a work piece therebetween,- a grinding wheel feeding mechanism, means including a solenoid to initiate an infeeding movement of the grinding wheel, and an electrical interlock including trip switches actuated by the longitudinal movement of the work supporting spindles, said trip switches being connected in series with the solenoid so as to prevent actuation of the solenoid when the spindles are separated.

6. An automatic cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces to said spindles each of which is operated by a separate fluid motor, a main control valve in controlof said grinding wheel and work carrier fluid motors, an electric solenoid to move, said valve in one direction to cause an infeeding movement of the grinding wheel, a cycle timing valve controlled by said valve, said cycle timing valve being in control of said spindle fluid motors, a trip switch associated with said spindles and arranged to be actuated when said spindles are separated, a cycle timing piston and cylinder to control the grinding cycle, an electric switch actuated by said cycle timing piston and cylinder,'and electrical connections between said trip switches, said electrically operated switch and solenoid, whereby the solenoid is rendered inoperative when th spindles are separated.

'7. An automatic'cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces to said spindles each of which is operated by a separate fluid motor, a main control valve in control of said grinding wheel and work carrier fluid motors, an electric solenoid to actuate said valve to cause an infeeding movement of the grinding wheel, a cycle timing valve controlled by said valve, said cycle timing valve being in control of said spindle fluid motors. a cycle timing piston and cylinder operagrinding tively connected with said valves and arranged to control the grinding cycle, an electric switch associated with each of said spindles, connections between said switches and spindles whereby the switches are actuated when the spindles are separated, and electrical connections connectingthe trip switches and solenoid'in series so as to prevent actuation of the main controlvalve while the spindles are separated.

- 8. An automatic cylindrical grinding machine having a transversely movable rotatable grinding wheel, a pair of opposed axially aligned work supporting and rotating spindles, a work carrier to convey work pieces to said spindles each of which is operated by a separate fluid motor, a main control valve in control of said grinding wheel and work carrier fluid motors, an electric solenoid to actuate said valve to cause an infeeding movement of the grinding wheel, a cycle timing valve controlled by said valve, said cycle timing valve being in control of said spindle fluid motors, a cycle timing piston and cylinder operatively connected with said valves and arranged to control the grinding cycle, an electric switch associated with said spindles, connections between said switch and spindles whereby the switch is actuated when the spindles are separated, an electric switch which is actuated by said spindles, an electric switch actuated by said cycle timing piston and cylinder, and electrical connections connecting said switches and solenoid in series with each other so as to prevent shifting of the main control valve and an infeeding movement of the grinding wheel when the work spindles are separated.

9. An automatic cylindrical grinding machine having a transverselymovable rotatable grinding wheel, a piston and cylinder to move said wheel in either direction, a pair of opposed aligned rotatable work supporting spindles, means synchronously to rotate said spindles, means including a fluid pressure piston and cylinder operatively connected to each of said spindles and arranged to movethe same toward and from each other to grip a work piece therebetween, a. pivotally mounted transversely movable work carrier, a hopper associated therewith, a fluid pressure piston and cylinder to move said carrier transversely, a fluid pressure piston and cylinder operatively connected to rock said carrier, a main control valve operatively connected to control the admission of fluid to said wheel feed cylinder and said work carrier cylinders, and a cycle timing valve operatively connected with said main control valve and arranged to control the admission and exhaust of fluid from said work spindle cylinders.

10. An automatic grinding machine comprising a transversely movable rotatable grinding wheel, means including a piston and cylinder to move said wheel transversely, a pair of opposed aligned rotatable work supporting spindles, means including an electric motor synchronously .to rotate said spindles, a fluid pressure piston and cylinder operatively connected to move each of said spindles, a work receiving hopper, a discharge chute, a pivotally mounted transversely movable work carrier having two work receiving pockets thereon, means including a piston and cylinder to move said carrier transversely simultaneously to grip a new piece of work and a ground piece of work supported on said spindles, means including a fluid pressure piston andcylinder to rock said carrier simultaneously to convey the ground work piece to the discharge chute and to convey the new work piece into axial alignment with the work spindles, and a main control valve operatively connected to control the admission of fluid to the grinding wheel cylinder, the work spindle cylinders and the work carrier cylinders so that the various elements are moved in timed relation with each other.

11. An automatic grinding machine comprising a transversely movable rotatable grinding wheel, means including a piston and cylinder to move said wheel transversely, a pair of opposed aligned rotatable -work supporting spindles, means including an electric motor synchronously to rotate said spindles, a fluid pressure piston and cylinder operatively connected to move each of said spindles, a work receiving hopper, a discharge chute, a pivotally mounted transversely movable work carrier having two work receiving pockets thereon, means including a piston and cylinder to move said carrier transversely simultaneously to grip a new piece of work and a ground piece of work supported on said spindles, means including a fluid pressure piston and cylinder to rock said carrier simultaneously to convey the ground work piece to the discharge chute and to convey the new work piece into axial alignment with the work spindles, and connections between said spindle cylinders and saidwork carrier cylinders whereby the rocking of the work carrier is interlocked withthe work spindles so that the carrier is held against rocking movement while the spindles are separated.

12. In an automatic cylindrical grinding. machine, a work loading device having a pivotally mounted transversely movable work carrier head thereon, a pair of spaced work receiving pockets on said head, means including a fluid pressure operated piston and cylinder to move said head ond operating position, and fluid pressure means I including a control valve mechanism operatively connected to said cylinder so as to first cause a transverse movement of said head, then a rocking movement of said head, then a transverse movement of said head in the reverse direction, and a rocking movement of said head in the opposite direction.

' 14. In an automatic cylindrical grinding machine having a pair of opposed axially aligned work supporting and rotating spindles, a work hopper, a work loading device comprising a pivotally mounted transversely movable work head thereon having a pair of spaced work receiving pockets simultaneously to grip an unground and a ground work piece, a discharge chute, means including a-piston and cylinder to move said head transversely simultaneously to grip an unground work piece supported in said hopper and a ground work piece supported on said spindles, and means including apiston and cylinder to rock said head so as to shift the unground work piece into alignment with said spindles and to shift the ground work piece into said discharge chute.

15. In an automatic cylindrical grinding machine having a pair of opposed axially aligned work supporting and rotating spindles, means including a fluid pressure piston and cylinder operatively connected to move said spindles toward and from each other, a work hopper, a work loading mechanism comprising a pivotally mounted transversely movable work carrier head, a pair of spaced work receiving pockets on said head, means including a piston and cylinder to move said head transversely simultaneously to grip a new work piece supported in said hopper and a ground piece of work supported on said spindles, means including a piston and cylinder to rock said head so as to discharge the ground piece of work and to present a new piece of work into axial alignment with the work supporting spindles, and a hydraulic interlock between said spindle actuating cylinders and said work carrier rocking cylinder whereby said latter cylinder is rendered inoperative until the work spindles have separated to release a ground piece of work.

16. In an automatic cylindrical grinding machine having a pair of opposed aligned work supporting and rotating spindles, a fluid pressure piston and cylinder operatively connected to each of said spindles and arrangedto cause them to approach or recede from each other, means synchronously to rotate said spindles, a work hopper, a discharge chute, a work loading device comprising a pivotally mounted transversely movable work carrier head thereon, a pair of spaced work receiving pockets on said head, means including a piston and cylinder to move said head transversely simultaneously to grip a work piece supported in said hopper and a ground piece of work supported on said spindles, means including a 'piston and cylinder to rock said head so as to simultaneously transfer said work pieces, and fluid pressure connections between one of said spindle cylinders and said work head rocking cylinder whereby said rocking cylinder is rendered inoperative until said work spindles have moved to an inoperative position.

17. In an automatic cylindrical grinding machine, a pair of opposed axially aligned work supporting and rotating spindles, means synchronously to rotate said spindles, means including a piston and cylinder to move each of said spindles toward and from each other, a work hopper, a discharge chute, a work loading device including a pivotally mounted transversely movable work carrier head, means including a piston and cylinder to rock said head so as to shift the work pieces simultaneously into alignment with said spindles andsaid discharge chute respectively, a main control valve to admit fluid to said first cylinder to move said work carrier head transversely, a cycle timing valveactuated by said main control valve, connections between said cycle timing valve and said spindle actuating cylinders to control the movement of said spindles in timed relation with the movement of said work head, and fluid pressure connections between one of said spindle cylinders and said work head rocking cylinder which are arranged to render said work head rocking cylinder inoperative until the work spindles have'separated and moved to an inoperative position.

HERBERT A. SILVEN. 

